1. Field of the Invention
The present invention relates generally to hardened shelters that protect above-ground structures from blast, storm, wind, fire, earthquake and other physical hazards. More particularly, the invention relates to such shelters that can be erected on-site by assembly of factory prefabricated, modular components. In some versions, camouflage and concealment of entryways into the shelters is provided to prevent unauthorized access or tampering with the above-ground structures within the shelters.
2. Background Art
Examples of above-ground structures that may be sheltered from blast, storm, wind, fire, earthquake and other natural hazards, as well as from attacks by military or terrorist organizations, include the following: oil pipeline valves; high voltage transformers; storage lockers containing personal items, first aid, medical and emergency security monitoring stations. To adequately protect such above-ground structures, such a shelter needs to be strong, capable of surviving blasts, even bomb blasts, fire-resistant if fire is a recognized hazard at the shelter's location, capable of such strong attachment to a ground surface as not to be dislodged even when subjected to very high wind force, cyclone or tornado, and secured against tampering and/or unauthorized entry by suitable locks, entryways and/or camouflage. Such a shelter should be easily erectable on site by assembling factory-prefabricated, modular components that require a minimum amount of materials to achieve the required strength, blast-resistance and other goals listed above. In the event an above-ground structure is expanded over a larger area of ground surface, the surrounding shelter should be easily expandable to accommodate the new, larger, above-ground structure by adding additional, modular components to the shelter.
The present invention assembles a shelter from modular, factory-prefabricated panels to minimize the amount of required materials while at the same time achieving the required strength and other goals, using equilateral triangular panels with attached frame members to form the sides of the shelter. To firmly attach the shelter to a ground surface, the present invention provides anchor assemblies to which lower ends of frame members attach. On-site installation of the shelter includes driving rebar through apertures in the anchor assemblies deep enough below ground to prevent dislodgement by blast or high velocity winds. The anchor assemblies that attach to the frame members include telescopic sections to facilitate installation of the shelter on sloped or uneven ground.
Various attempts have been made prior to the present invention to provide a shelter for above-ground structures and thereby achieve at least some of the above-listed goals. U.S. Pat. No. 490,779 to Zimmerman disclosed a shelter in the form of a rectangular pyramid for protection of a dwelling, barn or other above-ground structure against cyclones, wind, rain, and snow storms. Apertured, anchor irons attached to the four corners of the building were secured underground with stakes.
U.S. Pat. No. 6,151,841 to Green disclosed a prefabricated, portable, tornado shelter assembled from four equilateral triangular sides, a base frame, and a floor, to form a square, pyramid-shaped enclosure with latched doors and Plexiglas® windows. The shelter was held to the ground with four auger bolts.
U.S. Pat. No. 5,867,947 to Holt Hale et al. disclosed a folding pyramidal structure to surround and protect one or several people and bear extreme loads imposed by the collapsing of a building, induced, for example, by seismic waves during an earthquake.
U.S. Pat. No. 1,672,306 to Coupal disclosed a pyramidal tent with a square floor and tetrapod frame. The frame included four corner staffs or legs comprising telescopic sections disposed at the corner angles of the walls of the tent.
U.S. Pat. No. 5,400,541 to Ennamorato et al. disclosed a tepee tent for a tripod tree stand comprising a pyramidal tent having a triangular floor providing shelter for hunters and the like, and an upper platform that was supported by the tent and accessible by an external ladder. The tent could be secured to a ground surface by driving stakes into the ground through apertures in retention tabs at the three, lower corners of the tent.
Although none of the foregoing disclosures provided a shelter that could be assembled from modular components, U.S. Pat. No. 8,397,738 B2 to Livacich et al. disclosed a modular system for concealment and shelter. The system permitted configuring a number of concealment blinds or shelters using brackets, supports, segmented shafts, covers, curtains, skirts and more complex modules. Modules could include cover caps, including domes, cylindrical arches and pyramids.
Nevertheless, prior to the present invention, no system comprising factory prefabricated, modular components was known that could be easily assembled on-site to provide a shelter for an above-ground structure against blast, storm, wind, fire, earthquake and other natural hazards, as well as from attacks by military or terrorist organizations, and, in addition, could be readily expanded by adding thereto additional modular components in the event the shelter needed to be enlarged to accommodate an increase in size or number of above-ground structures.